From patchwork Thu Aug 25 14:20:36 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Liu Shixin X-Patchwork-Id: 12954734 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6A4F2C28D13 for ; Thu, 25 Aug 2022 13:46:07 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id B7C2494000A; Thu, 25 Aug 2022 09:46:03 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id B2C84940008; Thu, 25 Aug 2022 09:46:03 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 9CB0294000A; Thu, 25 Aug 2022 09:46:03 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0014.hostedemail.com [216.40.44.14]) by kanga.kvack.org (Postfix) with ESMTP id 8BE09940008 for ; Thu, 25 Aug 2022 09:46:03 -0400 (EDT) Received: from smtpin12.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id 5875BAB4A3 for ; Thu, 25 Aug 2022 13:46:03 +0000 (UTC) X-FDA: 79838238606.12.F9A2023 Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) by imf22.hostedemail.com (Postfix) with ESMTP id 1E23AC0011 for ; Thu, 25 Aug 2022 13:46:01 +0000 (UTC) Received: from dggpemm500020.china.huawei.com (unknown [172.30.72.55]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4MD4024WzdzkWcm; Thu, 25 Aug 2022 21:42:26 +0800 (CST) Received: from dggpemm100009.china.huawei.com (7.185.36.113) by dggpemm500020.china.huawei.com (7.185.36.49) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Thu, 25 Aug 2022 21:45:58 +0800 Received: from huawei.com (10.175.113.32) by dggpemm100009.china.huawei.com (7.185.36.113) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Thu, 25 Aug 2022 21:45:57 +0800 From: Liu Shixin To: Seth Jennings , Dan Streetman , Vitaly Wool , Andrew Morton CC: , , Liu Shixin Subject: [PATCH -next 2/3] mm/zswap: delay the initializaton of zswap until the first enablement Date: Thu, 25 Aug 2022 22:20:36 +0800 Message-ID: <20220825142037.3214152-3-liushixin2@huawei.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220825142037.3214152-1-liushixin2@huawei.com> References: <20220825142037.3214152-1-liushixin2@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.175.113.32] X-ClientProxiedBy: dggems703-chm.china.huawei.com (10.3.19.180) To dggpemm100009.china.huawei.com (7.185.36.113) X-CFilter-Loop: Reflected ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1661435162; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=vhfaLEVCMLX7fUMd/EfqiqVPx+NaC3/9ShKswlovgEE=; b=ndY8hfCeHV7sjZqLNHQDPZVRANQFIvyQWzZNBuqbhP0F5eN/5UiEd07d4LM4g3Fs7iZO0M gWCrVZi3nRrJN3IwAdwSEfBmwAeEyDW7hvnEjQ78um3icxa2LzWY8/0Yr+sxBbd02jIup7 JAcnx1y7B9dX7QQ18Alwl+hWVTucxbA= ARC-Authentication-Results: i=1; imf22.hostedemail.com; dkim=none; dmarc=pass (policy=quarantine) header.from=huawei.com; spf=pass (imf22.hostedemail.com: domain of liushixin2@huawei.com designates 45.249.212.187 as permitted sender) smtp.mailfrom=liushixin2@huawei.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1661435162; a=rsa-sha256; cv=none; b=okd+1g/qHUITn0riImY2FHQBD+x6K7Bbj5AAXWH3NjjwvTYig+SqO6DoHv18RNa46PHx38 842Dt70Hsju8zJ9v63wBM9ACvG3Ahkmmd03IQu3D930JMItdugVMJ2M68S8s4d6ofchGn1 pL2tEZP6qBjn3RIyxkxVGlLqg/LCPwM= Authentication-Results: imf22.hostedemail.com; dkim=none; dmarc=pass (policy=quarantine) header.from=huawei.com; spf=pass (imf22.hostedemail.com: domain of liushixin2@huawei.com designates 45.249.212.187 as permitted sender) smtp.mailfrom=liushixin2@huawei.com X-Rspamd-Server: rspam07 X-Rspamd-Queue-Id: 1E23AC0011 X-Stat-Signature: he8ipf8my1ueuofacd81dyrgoau551xa X-Rspam-User: X-HE-Tag: 1661435161-358864 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: In the initialization of zswap, about 18MB memory will be allocated for zswap_pool in my machine. Since not all users use zswap, the memory may be wasted. Save the memory for these users by delaying the initialization of zswap to first enablement. Signed-off-by: Liu Shixin --- mm/zswap.c | 48 +++++++++++++++++++++++++++++++++++++++--------- 1 file changed, 39 insertions(+), 9 deletions(-) diff --git a/mm/zswap.c b/mm/zswap.c index 84e38300f571..90df72aceb08 100644 --- a/mm/zswap.c +++ b/mm/zswap.c @@ -81,6 +81,8 @@ static bool zswap_pool_reached_full; #define ZSWAP_PARAM_UNSET "" +static int zswap_setup(void); + /* Enable/disable zswap */ static bool zswap_enabled = IS_ENABLED(CONFIG_ZSWAP_DEFAULT_ON); static int zswap_enabled_param_set(const char *, @@ -220,6 +222,8 @@ static atomic_t zswap_pools_count = ATOMIC_INIT(0); /* init state */ static int zswap_init_state; +/* used to ensure the integrity of initialization */ +static DEFINE_MUTEX(zswap_init_lock); /* init completed, but couldn't create the initial pool */ static bool zswap_has_pool; @@ -273,13 +277,13 @@ static void zswap_update_total_size(void) **********************************/ static struct kmem_cache *zswap_entry_cache; -static int __init zswap_entry_cache_create(void) +static int zswap_entry_cache_create(void) { zswap_entry_cache = KMEM_CACHE(zswap_entry, 0); return zswap_entry_cache == NULL; } -static void __init zswap_entry_cache_destroy(void) +static void zswap_entry_cache_destroy(void) { kmem_cache_destroy(zswap_entry_cache); } @@ -664,7 +668,7 @@ static struct zswap_pool *zswap_pool_create(char *type, char *compressor) return NULL; } -static __init struct zswap_pool *__zswap_pool_create_fallback(void) +static struct zswap_pool *__zswap_pool_create_fallback(void) { bool has_comp, has_zpool; @@ -782,11 +786,17 @@ static int __zswap_param_set(const char *val, const struct kernel_param *kp, if (!strcmp(s, *(char **)kp->arg) && zswap_has_pool) return 0; - /* if this is load-time (pre-init) param setting, + /* + * if zswap has not been initialized, * don't create a pool; that's done during init. */ - if (zswap_init_state == ZSWAP_UNINIT) - return param_set_charp(s, kp); + mutex_lock(&zswap_init_lock); + if (zswap_init_state == ZSWAP_UNINIT) { + ret = param_set_charp(s, kp); + mutex_unlock(&zswap_init_lock); + return ret; + } + mutex_unlock(&zswap_init_lock); if (!type) { if (!zpool_has_pool(s)) { @@ -876,6 +886,14 @@ static int zswap_zpool_param_set(const char *val, static int zswap_enabled_param_set(const char *val, const struct kernel_param *kp) { + if (system_state == SYSTEM_RUNNING) { + mutex_lock(&zswap_init_lock); + if (zswap_setup()) { + mutex_unlock(&zswap_init_lock); + return -ENODEV; + } + mutex_unlock(&zswap_init_lock); + } if (zswap_init_state == ZSWAP_INIT_FAILED) { pr_err("can't enable, initialization failed\n"); return -ENODEV; @@ -1432,7 +1450,7 @@ static const struct frontswap_ops zswap_frontswap_ops = { static struct dentry *zswap_debugfs_root; -static int __init zswap_debugfs_init(void) +static int zswap_debugfs_init(void) { if (!debugfs_initialized()) return -ENODEV; @@ -1463,7 +1481,7 @@ static int __init zswap_debugfs_init(void) return 0; } #else -static int __init zswap_debugfs_init(void) +static int zswap_debugfs_init(void) { return 0; } @@ -1472,11 +1490,14 @@ static int __init zswap_debugfs_init(void) /********************************* * module init and exit **********************************/ -static int __init init_zswap(void) +static int zswap_setup(void) { struct zswap_pool *pool; int ret; + if (zswap_init_state != ZSWAP_UNINIT) + return 0; + if (zswap_entry_cache_create()) { pr_err("entry cache creation failed\n"); goto cache_fail; @@ -1534,6 +1555,15 @@ static int __init init_zswap(void) zswap_enabled = false; return -ENOMEM; } + +static int __init init_zswap(void) +{ + /* skip init if zswap is disabled when system startup */ + if (!zswap_enabled) + return 0; + return zswap_setup(); +} + /* must be late so crypto has time to come up */ late_initcall(init_zswap);